Fused safety switch



March 2, 1937.

A. CORBETT 2,072,730 FJSED SAFETY SWITCH Filed D80. 6, 1935 4Sheets-Sheet l I 28 f7 I is H 1 (3 O O O 3/) CO v TTORNEYQS March 2,1937. A. CORBETT 2,072,730

FUSED SAFETY SWITCH Filed Dec 6, 1935 4 Sheets-Sheet 3 ATTORN EYS 4Sheets-Sheet 4 A. CORBETT FUSED SAFETY SWITCH Fi led Dec. 6, 1935 March2, 1937.

A V i f w a. z wmmwmmvvmwh INVENTOR 6 m BY 5% ma MM ATTORNEYS 15desirable that vg receptacle.

V30 conductors to the 35f switch, considered as a whole,

Patented Mar. 2,1937

PATENT OFFICE 7 2,072,130 FUSED SAFETY SWITCH' Alfred Corbett. n-win, n,

Electric Products Corporati Delaware assignmto Nationalon, a corporationof Application December 6, 1935, Serial No. 53,174 9 claims. (oi.200-114) the switch, within the cabinet, to protect a greater Thisinvention relates to a fused safety switch, to the combination of afused safety switch with, specialized means for leading electrical powerto and from the switch,

' switch with a fuse cabinet pe- In fused switch assemblies in whichfuses are associated with switching means to protect line circuits, orspecial circuits, 'such as range circuits, l0 it is of importance thatthe fuse-containing'assembly be of relatively restricted dimensions, inorder that it may be housed in a cabinet of moderate size, while leavinwithin the cabinet working space for the connection of conductors. It isfused safety switches be formed of a receptacle element and a coverelement, with the fuse mounted on the under side of the cover. element,and with the cover element hinsedly mounted to the receptacle. Thedisadvantage with a structure, as so generally described, is that thehinging of the cover to the receptacle causes the cover to occupy whatis considered in the art to be an unreasonable space, when the cover isin its open position to expose the interior of the This eithernecessitates the use of a fuse cabinet of relatively great size toaccommodate the switch in both its positio or, in a fuse cabinet ofrestricted dimensions, gives cramped space within the cabinet for theattachment of fused switch. With these problems in mind, I have inventeda fused safety switch in which a fuse-carrying cover element is sopivoted to its associated receptacle that in open position occupies amini- 'mized space;'and with this fused safety switch I have associateda containing cabinet so formed and arranged as to he peculiarly adaptedto the accommodation of my fused safety switch, and 40 also to occupyitself a minimized space while providing interiorly of the cabinetabundant free working space for the attachment of conductors to thefused switch. This fuse cabinet I also have made of such form andarrangement that, when 45 the fused safety switch is mounted therein,the

assembly presents a compact and pleasing appearance.

In evolving the fused safety switch of my invention, and my combinationof fused safety 50 switch and containing cabinet for it, I havesucceeded in associating with the switch inlet connector elements ofunitary structure, and have also associated in the cabinet and with theswitch unitary fuse-mounting elements so constructed, 65 and arrangedthat they may be integrated with and to the combination ofv of the coverthe or lesser number of branch circuits, without alteration in orremoval of the fused safety switch itself.

' In the unitary connector structures for leading of! branch circuitsfrom the switch I have also incorporated tamper-proof structures ofknown form in such manner that they are not removable from mountedposition without removing the switch assembly from the cabinet anddisintegrating the assembly by detachmentof its outlet connectorelements.

The structure and arrangement of my fused safety switch assembly is suchas to adapt the switch to varied service in the fused protection ofcircuits, andwithout substantial alteration in the structure of theswitch itself to permit its ready adaptation to various servicerequirements.

In the accompanying drawings Fig. I is a front elevation, showing thecabinet and fused safety switch of my invention with the safety switchand branch circuit fuses exposed by open position of the cabinet door,and with the remaining spaces within the cabinet enclosed.

mg. II is an end elevation of the cabinet shown inFig. I.

Fig. III is a view, looking in the direction of the arrows I1I-I1I ofFig. I, showing the assembly of the cabinet and the fused safety switchtherein, walls of the cabinet being partially broken away to show inside elevation the safety switch .contained within the cabinet.

Fig. IV is a plan view of the receptacle portion of my fused safetyswitch, cover elements therefor being omitted, showing, switch proper,added connector elements for inlet connection and outlet connection byway of fused branch circuits from the switch, and showing in dottedlines buss connectors associated directly with the switch.

Fig. V is'an exploded side elevational view, on

a slightly enlarged scale, illustrating surface contours only, of thereceptacle portion of my fused safety switch proper, and unitary inletand outlet connector elements for integrated association with thereceptacle of the switch proper.

Fig. Va is a side elevational view, on the scale of Fig. V, showing inside elevation the cover element of my fused safety switch, and showingfuses of the cartridge type mounted on the under face thereof forpresentation to the interior of an associated receptacle.

associated with the Fig. Vb is an end elevation of the cover element' Ishown in Fig. Va.

Fig. Vc is an end elevation showing, on a scale larger than that ofFigs. V, Va, and Vb, a structural base element or block adapted forintegration with the fused safety switch to provide for the mounting andconnection of the sockets for 6 branch circuit fuses at the outlet endof the switch.

Fig. Vd is, on the scale of Fig. Vc, a view of two structural elementsor blocks adapted for mounting on the base block of Fig. V to receiveand house fuse sockets mounted on the base block of Fig. Va and to housefuses received in such sockets, one of the said structural shield blocksbeing shown wholly in end elevation, and the other of the said blocksbeing shown partly in end elevation and partly in vertical section;

Fig. Ve shows in end elevation, on the scale of Fig. Vc, two structuralelements or blocks adapted to be integrated with the receptacle of thefused switch to provide inlet connection thereto.

0 Fig. VI is a transverse, vertical, sectional view, taken on theirregular section line VI-VI of Fig. IV, illustrating, on a stillfurther enlarged scale, the structure within the receptacle at one sideof the switch, as shown in Fig. IV, with the cover shown thereon inclosed, circuit-completing condition of the switch, and taken verticallythrough an end wall of the receptacle at the other side of the switchstructure. K

Fig. VII is a. longitudinal, vertical sectional view, on the scale ofFig. VI, taken on the section line VII VII of Fig. VI, and showing inbroken lines an intermediate position of the cover in rotation of thecover to expose the interior of the receptacle; this view alsoillustrating in longitudinal, vertical section the integration of theunitary structural blocks forming inlet and outlet connectors for theswitch, and showing a tamperproof socket mounted on the base block atthe outlet end of the switch and housed in a shield block assembled onthe base block.

Fig. VIII is a plan view of a modified safety switch assembly, shown onthe scale of Fig. IV, showing. the switch as of single construction,rather than as of the double construction shown in preceding figures ofthe drawings, and showing mounted at both ends of the switch the simpleform of connector block illustrated as an inlet connector in thepreceding figures of the drawings.

Fig. IX isa. plan view. similar to Fig. VIII, and on the same scale, butshowing at the outlet end of'the switch proper a base block for themounting of branch circuit fuse sockets formed sub stantially asone-half the base block shown in Fig. Vc.

Fig. X is an end elevation of the single unit base block shown inassembly in Fig. IX.

Fig. XI is a view, taken in vertical, longitudinal section, on the scaleof Figs. VI and VII, illustrating a modification in the barrierstructure of the switch arranged fully to shield the contacts in thereceptacle of the switch during movement of the'cover to open position,and illustrating an intermediate stage in such movement in order toillustrate the shielding of the contacts.

Fig. XII is a cross-sectional view through the switch, taken on thesection line XIIXII of Fig. XI.

Referring to the drawings, reference numeral designates generally thecabinet for containing the safety switch, which is shown with its door 2in open position, exposing to view two separately operable switch units3 and 4, and plug fuses 5 .for the protection of branch circuits takenoff from the switches.

Referring now particularly to-the structure and arrangement of theswitch assembly itself, it is to be noted that the two switches,designated respectively by reference numerals 3 and 4, are shown asassociated together, and having a common neutral bar 6. It should' beinitially explained that the direct association of two switch units, oneof which may protect the line circuit, and the other of which mayprotect a special circuit, such as a range circuit, may be made eitherby the use of an integral molding for the receptacle elements of the twoswitch units, or by forming the receptacles of the two switch units separately, and integrating them in the assembly. Also, as will appear, oneof the switch units, comprising an assembly of receptacle, cover, andcon.- nectors, may be independently used. Also, in line with thisthought, more than two switch units may be assembled together, either bythe use of a molding comprising more than two receptacles, or by theintegration of more than two initially separate receptacles.

Referring particularly to the structure of the switch, best shown inFigs. V to VII, inclusive, of the drawings, each of the receptacles l isformed of insulating material, molded or otherwise formed into anintegral body having a bottom wall 8, end walls 9 and I0, and side wallsII and I 2, the side wall I2 being, as shown in these figures of thedrawings, common to the two receptacles of the assembly. At itslongitudinal center line the receptacle is divided into two chambers ofsubstantially equal area by a barrier l3, which is integrally formedwith the body of the receptacle. In one of the chambers defined by thebarrier l3 are spring contacts I 4 and I5, and in the other of thechambers are spring contacts is and I! of polarity opposite to that ofthe spring contacts i4 and I5. Associated with spring contacts 14 andI6, at the inlet end of the receptacle, are fiber shields i8, arrangedto extend upwardly along that element of the spring contacts which liesinwardly of the receptacle. The spring contacts l5 and I! may, for thereason hereinafter explained, be unshielded. The cover 20 of thereceptacle carries on the under face thereof spring clips 2| and 22,-adapted to receive and engage cartridge fuses 23. Conductivelyassociated with the cartridge fuses 23 on the under face of cover 20 arecontact blades 24, 25, 26, and 21, the contact blade 26 being cut offfrom view by contact blade 21 in Fig. Vb and by contact blade 24 inFigs. VII and Va. v In closed, circuit-completing condition of theswitch the circuit is completed on one side of barrier l3 by springcontacts I4, contact blade 24, the cartridge fuse 23 interconnecting thetwo spring clips 2|, contact blade 25, and spring contacts IS. Thecompletion ofa conductive assembly through the cartridge fuse 23 at theother side of barrier I3 is identically effected by the elementsassembled at that side of the fuse.

Cover 20 is articulated to the body of receptacle I, so that itmay beswung into open position to expose the interior of the receptacle, andto expose the fuse-attaching elements and the fuses carried on the underface of the cover. For swinging movement, cover 20 is provided with ahandle 28, which is shown as of simple form, but which may be of anysuitable specialized form if so desired, and is mounted on a pintle 30,trunnioned in the side walls of the receptacle. As best illustrated inFig. I of the drawings, pintle 30 is common to the covers 20 associatedwith both the switch units, being mounted in upwardly extended lugs 3|,formed on the outer side wall ll of the receptacle, and lying in agroove 32 (see Fig. IV) in the common side wall ii. The pintle isoverlaid at the common 5 side wall I! by a strap If shown in Fig. I.Pintle 30 is thus so engaged by groove 32 and strap 33 that it is heldagainst longitudinal movement and against rotation. Returning to aconsideration of one of the two 0 receptacle and cover assemblies shownin duplicate in these figures of the drawings, it will be noted thatpintle 30 extends through the body of the cover 20 forwardly-l-thatis,to the left in Fig. VII-of the rearward edge of the cover, and that itis slightly above the upper edges of the outer side wall ll of thereceptacle. The cover thus'has a center of rotation intermediate itsends and substantially removed forwardly from its rearward end, so thatin swinging movement 0 of the cover into open position the rearwardregion of the cover follows a path extending into the hollow interior ofthe receptacle, and in fully open position the rearward region of thecover overlies the rearward region of the receptacle. It will be notedby an inspection of the drawings, that the positioning of the pintle'lllis such as to cause the cover, in its open position, to overlie thereceptacle to the maximum extent possible without increasing the depthof the receptacle.

In order, at the rear of the switch structure; to permit turningmovement of the cover, barrier I3 is provided with an arcuate recess 35centered on the pintle iii, and a barrier portion It depends from theunder face of the cover in alignment with the barrier ll. This barriermember 38 is of segmental form, and also has its edge formed on an arccentered in the pintle Iii. In receptacle-closing position of the cover,barrier member 38. therefore lies inthe 40 recess 35 of barrier II toform a complete. barrier extended from end to end of the receptacle.

In opening movement of cover 20, the equally curved surfaces of recessI5 and barrier member 36 permit free turning movement of the cover. '45At the forwardxor inlet end of the switch, the

forward wall 0 of the receptacle may be chamfered as at 31, and thelower forward edge of the cover may be chamfered as at 007 to permitturning movement at the forward end of 50 the cover within the overallthickness of the front wall 9. I

It will be appreciated that, with the cover 20 swung further than itsposition as shown in Fig. VII, the cover in its reversed positionoverlies 55 almost half the length of the receptacle. In

addition to economizing in the overall longitudinal dimensions of theswitch when the cover is in open position, the'cover, when opened, thusalso screens spring contacts l5 and IT at the outlet end of thereceptacle, and for this reason it is unnecessary that these contacts beprovided with insulating shields, such as the insulating shields IIwhich shield spring contacts I4 and ii at the inlet end of thereceptacle.

grated with the switch proper by attachment both to bus bars leading toand from the switch. To this end, I provide inlet connector blocks 80,and outlet connector or base blocks 40. Ex-

tending longitudinally in each of the inlet con- 15 nector blocks 39 area pair of stepped recesses matching It being necessary to provide forelectrical of the,connector units and the switch proper "0, adapted toreceive line connectors II, and for the mounting of bars 42, of oppositepolarity, leading to the spring contacts I and I, through slots 43 inthe end wall 8 of the switch. Beneath inlet connector block 39 arehollow feet or thimbles b to receive the heads of screws 44 forattaching conductors to the block. Each block is also provided with anadditional foot c, in line with a bore 39d, through which may extend thescrew for securing the block in the fuse or switch cabinet in which theassembly is mounted. These feet on the connector are of equal heightwith screw-receiving feet 1a formed at the under side of thereceptacle 1. It will be noted that in the double form of switch shownin Figs. 1 to VII, inclusive, of the drawings, two inlet connectorblocks unit of the structure. The formation of the inlet connectorblocks 39 as units, each of which is adapted for integration in a switchunit, permits these blocks to be used without change in either a singleswitch assembly or a multiple switch assembly.

At the outlet end of the receptacle 1, the outlet base blocks areintegrated. These base blocks 40 desirably are formed to extend acrossthe entire width of the double switch receptacle, to-

provide for cross connection between the switches in the manner which isto be described. Each of the blocks has thereon feet 400 and 40b of aheight equal to the feet on the receptacle I and on the inlet connectorblock 39. Of these feet, the feet "b have therethrough central bores 'toreceive screws for mounting the base blocks to the fuse or switchcabinet. Recesses 40c extend forwardly from the rearward edge of theblock in the lower region of the block, these recesses being adapted toreceive conductor bars 45, leading from spring contacts within thereceptacle through slots in the end wall "I of the receptacle. Asimilarly formed, but intermediately positioned, .pair of recesses 40dare adapted to. receive conductor bars 46, also passed through slots inthe end wall in of the receptacle from spring contacts within thereceptacle.

As shown, the recesses 40c and 40d do not extend wholly through theblock 40, so that the block 4. is adapted solely to use as a final baseblock at the outlet end of the receptacle. If it is desired to use twoor more base blocks, in order to provide mounting for an additionalnumber of branch circuits taken off from the switch, intermediate baseblocks are inserted between the outer or final base block 40, and thereceptacle of the switch.. Such base blocks, for intermediate use,differ from the base block 40 only in the fact that the recesses lie and40d are extended throughout the entire width of the block to providechannels through which the conductor bars may be extended into anadditional outlying block or blocks.

Base block 40 is provided with a plurality of apertures 40c, one leadingfrom each of the recesses in the base block to the upper surface of theblock. These bores receive bolts, or the like, 41, making connectionwith conducting bars I and 40, and serving each-as the center contact ofa socket for a plug fuse guarding a branch circuit. The fuse socketsshown areof the tamper-proof type, each comprising a screw shell 8,which has fixed therein a tubular structure 40, containing a conductingplunger 80 urged away from the center contact by a coil spring I. Thesestructures, which in themselvesdo not form part of my invention, areadapted,

upon the insertion of plug fuse 5, to complete connection between thecenter contact provided by bolt 41, and the screw shell 48.. From eachof the screw shells 48 a branch conductor 'bar 52 leads to a terminalpost 52a.

Since the tamper-proof nature of the fuse socket renders the centralconnections of the socket inaccessible when the tubular guard 49 ispermanently secured in the screw shell 48, it is highly desirable thatthe means for housing and shielding the sockets be formed of an integralelement or elements mountable on and removable from the base block 40.These housings or guard blocks 53 are shown as formed integrally each tohouse two fuse sockets in vertical bores 53a extended through theblocks. Each of the blocks has through the forward wall thereof slots53b to lead to the branch-conducting bars 52 from the fuse sockets intoa terminal receiving space lying between abutments 53c. Through each ofthe blocks 53 is a screw-receiving bore 53d, which is adapted inassembly to align with the bore terminating in one of the feet 40b ofthe base block 40, this alignment providing through passage for a screwmaking connection between the blocks 40 and 53 by through attachment tothe base of the fuse or switch cabinet in which the assembly is mounted.

This outlet structure readily adapts itself to multiplication forleading off additional branch circuits. base blocks the slightlymodified form of block described above/base blocks 40 and housing blocks53 may indefinitely be multiplied along the neutral bar 6 associatedwith the switch structure, and along extended conductor, 'or buss, bars45 and 46. Also, this unit construction of the outlet connectors adaptsitself readily to the use of tamper-proof fuse sockets, of the typeindicated above, to protect the various branch circuits which are ledoff. b

To describe an outlet connection, usable with the unit switch assemblyshown, reference is to be had particularly to Figs; IV, VI and VII ofthe drawings. In Fig. IV it will be seen that the conducting bars 45 areinterconnected at the receptacle by means of a U-shaped conducting bar54, which interconnects the spring contacts I of one receptacle assemblyand the spring contacts I! of the other receptacle assembly; Theintervening conducting bars 46, leading from the spring contact H of onereceptacle'assembly, and the spring contact I5 of the other receptacleassembly, are interconnected between the fuse sockets which they sgve byconducting bar 55. Appropriate electrical connection may be made invarious alternative ways, since unit construction of the outletconnector blocks lends itself to variety in the efiective connection ofbranch circuits, as well as to multiplication in the branch circuitstaken off, with the change in the form of any of the structuralelements.

Turning now to the fuse or switch cabinet I,

and to the mounting of the switch structures in the cabinet, it will beseen that the door 2 of the cabinet encloses an intermediate region onlyof the cabinet, and that this door 2 is a structure arranged to projectoutwardly from the cabinet body Ia. This arrangement of the cabinet door2 permits the switch structure proper to be enclosed within the compassof the cabinet whether the cover of the switch be in closed positionorin open position. Thelength of the protuberance provided by thecabinet door 2 is, however, minimized by the mounting of the switchcover 20.

This because, utilizing as intermediate In installation, the baseportion Ia of the cabinet may be inset from the surface of a wall withits outer facelying flush with the wall surface, so that merely theprotuberance formed by the door 2 projects outwardly beyond the surfaceof the wall.

The means for enclosing the interior of the cabinet to both sides of thedoor 2 are detachable cover members 56 and 51, which have on eachthereof peripheral flanges 58 embracing the wall of the cabinet body Ia.Inwardly of the cabinet the cover element 56 has a dependent flange orwall 59, separated from the embracing flange 58 by slots. Thisconstruction permits wall 59 to lie between the body walls embracedbythe flange 58, providing a finishing stub partition interiorly ofthe'cabinet cooperative with the adjacent edge of the door 2, andproviding an interlocked engagement between the cover element and thebody of the cabinet.

Cover element 5! has thereon a generally similar interiorly'dependingwall 60, which is similarly separated by slotting from the flange 58 ofthis cover element. Wall 60 is, however, inclined longitudinally of theassembly, and is extended in forward inclination to a line at which itcontacts the upper surface of socket-embracing blocks 53. Thisarrangement of the door and cover element separates the space occupiedby the switch and plug fuses from the remaining space within thecabinet, and presents a particularly finished and attractive appearancewhen the door of the cabinetis open.

It will readily be understood that the fundamental form of the fuse orswitch cabinet and its cooperative relation to the switch assembly maybe preserved in installations in which additional connector units areadded to the switch assembly, for taking off additional branch circuits.This involves merely such changes in the proportions of the cabinetelements that one or more rows of fuses 5 are exposed inwardly of theinclined partition wall 60 of the cabinet cover element 51.

Fig.' VIII of the drawings shows a substantially identical receptaclestructure formed as a single switch. This single switch receptacle,designated generally by reference numeral BI, is adapted for use merelyas a line switch, either fused or unfused, by mounting at the outlet endof the switch an inlet block 39 identical with the inlet block by whichinlet connection is made to the switch.

I In this form, in which fuse mounting for branch circuits is notdirectly associated with the switch, the structure of the switch, as toits receptacle and cover structure and arrangement, is substantiallyidentical with that previously described, the cover being mounted on thereceptacle to turn about an axis intermediate its length, and thereceptacle and cover being provided with barriers I 3 and 36, identicalwith the similarly designated elements shown in the preceding figures ofthe drawings. In this single switch structure also only the springcontacts I4 and I 6 at the inlet end of the receptacle need be guardedby feet 620. disposed at the'side-edges of the block, and a foot 62bthrough which extends a bore for a mounting screw. It has extendedforwardly from its rearward edge recesses 620 for the reception andattachment of conducting bars. 4

In both the showing of Fig. VIII and the showfused branch circuits takenof! from the switch In Figs. XI and XII, there is illustrated amodification in the switch structure designed particularly to preventdanger to an operator of the switch while moving tween its open andclosed positions. This modified structure is shown as incorporated in asingle switch, corresponding generally to the switch shown in Figs. IXand X of the drawings, but it is to be, of course, understood that it isapplicable to an arrangement comprising two or more switch units.

Referring to these figures of the drawings, it is in the upper edgecontour of the barrier, therein shown, that the modified receptaclestructure resides. This barrier 65 has in its upper region an arcuatelydefined recess 65a,

' corresponding to the arcuate recess 35 previously lapping of the cover.not pass upwardly described as formed in barrier l3. Forwardly ofrecess 65a there is a region 65b which lies within a groove 66a in cover66. Forwardly of this region 65b is a region 65c in which the barrier 85is extended still farther upwardly to lie in a through slot 66b in thecover 66'.

Dependent from adjacent the inlet end thereof, are two insulating wings61 arranged, in closed position of the cover, to embrace the inletregion of the barrier adj acent the spring contacts II and I6 therein.The over- 68 with barrier 65, by means of the slotted embracement ofbarrier portion "0, together with the downward extension of insulatingwings 61, is such that, in opening movement of the cover, the coverstructures do beyond the barrier until contact blades 24 and 26 havebeen wholly with drawn from contact with the spring contacts I4 and Hi.This arrangement provides means in the primary partsof the assembly forshielding the contacts, and thereby prevents accidental bridging acrossthe sw itch during opening movement of the cover.

Similarly, in swinging the cover from open position to its closedposition, the contact blades 24 and 28 do not come into contact with thespring contacts II and I6 before the insulating wings 61 to some extentoverlap the barrier portion 850 which they embrace. With this struconlyagainst ture, the operator is protected not danger under ordinaryconditions, but is also protected -against extraordinary conditionswhich conceivably may arise.

It will be noted that the receptacle element of the switch is so formedthat for most simple connections it may be reversed, the outlet end ofthe switch becoming the inlet end thereof, and viceversa. The terms"inlet and outlet have been used throughout the specification for purofconvenience in describing the location of the various switch parts.These terms are to the switch cover bethe under face. of the cover beread in the light of the showing of the drawings, and are not to beconsidered terms of limitation as defining a fixed relationship ofswitch parts in the switch proper peculiarly for either inlet or outletconnection. It is also to be understood that my safety switch, and allthe various modifications illustrated, may be used as an unfused switchby interconnecting the blade contacts on opposite sides of the cover bysimple conductors rather than by fuses. In such case, also, suitablefuses may be mounted, and electrically connected in the receptaclerather than on the cover to be made a part of through circuits by thecooperation of the cover-carried contacts.

It has been noted in an early portion of the specification thatamultiple switch assembly may be made up by integrating together unitaryreceptacles, such as the receptacles shown in Figs. VIII and XI, insteadof forming an integral multiswitch receptacle. The description of thefundamental structure, and modifications, hereinabove contained, rendersclear how, this may readily be done.

Throughout the drawings the structural parts have been shown of a wallthickness appropriate to the use of porcelain as the material out ofwhich the primary elements are made. be understood that, if these partsare made of some suitable hot molded insulation, such as the moldingresin compositions, the thickness of the bases and walls can besubstantially reduced, thus further reducing the compactness ofstructure obtained in principle by the shape and arrangement of theparts.

It will readily be understood that such various modifications in andadaptations of my switch do not affect the novel and advantageousfeatures which I have succeeded in incorporating in a switch of the sortinvolved, and which have with particularity been described and explainedabove.

I claim as my invention:

1. In a safety switch assembly the combination of a hollow insulatingreceptacle, contacts mounted in the receptacle and spaced longitu- Itwill H dinally of the receptacle in cooperative pairs, an

insulating cover for the receptacle having on its under face contactselectrically interconnected longitudinally of the cover in pairs each ofwhich in closed position of the cover electrically interconnects alongitudinally spaced pair of contacts in the receptacle, said coverbeing arranged in closed position to overlie substantially the entirecavity of the receptacle, and trunnions intermediate the length both ofthe cover and the receptacle and arranged for turning movement of thecover about a fixed axis whereby when swung to open position exposingthe contacts on the under face of the cover regions of the cover lyingadjacent the turning axis to both .60 sides thereof partially overliethe interior of the receptacle to shieldcontacts at one end of thereceptacle.

lating the cover to the receptacle to turn about an axis intermediatethe length of the cover thereby to overlie a region of the receptacle inopen position of the cover, a recess in the barrier of the receptaclehaving an edge formed on an are centered in the axis of the cover, and adepending wall on the cover having an edge also formed on an arecentered in the axis of the cover, said wall and recess cooperating topermit swinging movement of the cover to fully open position andcooperating to form in closed position of the cover a complete barrierfrom end to end of the receptacle. 7

3. In a safety switch assembly the combination of a hollow insulatingreceptacle having mounted therein cooperative contacts spaced from eachother longitudinally of the receptacle, an insulating cover for thereceptacle having on the under face thereof contacts electricallyinterconnected longitudinally of the cover and positioned on the coverin closed position thereof electrically to interconnect thelongitudinally spaced contacts in the receptacle, an insulating blockarranged to carry inlet connection to at least one contact at the inletend of the receptacle, and at least one separately formed insulatingblock adapted for integration with the switch receptacle at the outletend thereof and adapted to carry both outlet connections to at least onecontact at the outlet end of the receptacle and to carry a fuse socketfor the fusing of a circuit led off from said outlet connection, and atleast one separately formed insulating block adapted for integration inthe assembly by attachment to the block carrying the fuse socket andarranged to house a fuse socket carried by said first-named block.

4. In a switch assembly the combination of a switch receptacle having anoutlet conductor projected therefrom, a separately formed insulatingblock adapted to receive said conductor in a region below the uppersurface of the block, a fuse socket mounted on said insulating block andhaving a contact structure projected through the said block andconnected with the conductor housed therein, said fuse socket havingfixed therein means screening the said contact structure from above, anda separately formed insulating block arranged to receive and house saidfuse socket and adapted for integrating attachment to the insulatingblock carrying the fuse socket.

5. In a safety switch assembly the combination of a hollow insulatingcontact-containing receptacle, and an insulating contact-carrying cover,said cover being arranged in closed position to overlie substantiallythe entire cavity of the receptacle, and trunnions intermediate thelength both of the cover and the receptacle and-arranged for turningmovement of the cover about a fixed axis, whereby in its open positionthe.

cover partially overlies the cavity of the receptacle.

6. In a safety switch assembly the combination of an insulatingcontact-containing receptacle, and an insulating contact-carrying coverarticulated to turn about an axis intermediate the ends of the coverthereby partially to overlie the receptacle in'open position of thecover, with an insulating block arranged to carry inlet connection to atleast one contact at the inlet end of the receptacle, and at least oneseparately formed insulating block adapted for integration with theswitch receptacle at the outlet end thereof and adapted to carry outletconnection to at least one contact at the outlet end of the receptacleand also to carry a fuse socket for the fusing of a circuit led off fromsaid outlet connection, and at least one separately formed insulatingblock adapted for integration in the assembly by attachment to the blockcarrying the fuse socket and arranged to house a fuse socket carried bysaid first-named block.

7. In a safety switch assembly the combination of an insulatingcontact-containing receptacle, and an insulating contact-carrying coverarticulated to turn about an axis intermediate the ends of the-coverthereby partially to overlie the receptacle in open position of thecover, an outlet conductor projected from the said contact-containingreceptacle, a separately formed insulating block adapted to receive saidconductor in a region below the upper surface of the block, a fusesocket mounted on said insulating block and having a contact structureprojected through the said block and connected with the conductor housedtherein, said fuse socket having fixed therein means screening the saidcontact structure from above, and a separately formed insulating blockarranged to receive and house said fuse socket and adapted forintegrating attachment to the insulating block carrying the fuse socket.

8. In a fused safety switch assembly the combination of an insulatingcontact-containing receptacle, an insulating cover carryingfuse-interconnected contacts cooperative with the contacts of thereceptacle electrically to interconnect the receptacle-containedcontacts through the covercarried fuse in closed position of the cover,and means articulating the cover to the receptacle to turn about theaxis intermediate the ends of the cover thereby in open position of thecover partially to overlie the receptacle, with at least one separatelyformed insulating block adapted for integrationwith the saidcontact-containing receptacle at the outlet end thereof and adapted tocarry outlet connection to at least one contact at the outlet end of thereceptacle and also to carry a fuse socket for the fusing of a circuitled off from said outlet connection, and at least one separately formedinsulating block adapted for integration in the assembly by attachmentto the block carrying the fuse socket and arranged to house a fusesocket carried by said first-named block.

9. In a safety switch assembly the combination of an insulatingcontact-containing receptacle, and an insulating contact-carrying coverarticulated to the receptacle to turn about an axis intermediate theends of the cover thereby partially to overlie the receptacle in openposition of the cover, with at least one separately formed insulatingblock adapted for integration with the said contact-containingreceptacle and adapted to receive and mount electrical outlet connectionto at least one contact contained in the said receptacle.

ALFRED CORBETT.

